The present invention relates to fluid dispensing systems.
In the agrochemical field, chemicals are supplied in bulk and in concentrated form. However, for the smaller consumer, such bulk supplies are often too expensive and quite difficult to store safety. Accordingly, there is a need to enable the smaller user to obtain a single dose of the chemical in an economic and safe manner. For this purpose, it is proposed to supply the or each consumer with a refillable smaller container, capable of storing a single dose of chemical, either in liquid or powder format, which container is specific to a particular chemical and to supply each retailer with a dispenser which can safely dispense the selected chemical to the chemical specific small container only.
The small container will hereinafter be referred to as a xe2x80x9cshuttlexe2x80x9d since it is shuttled between the retailer and the point of use. At the point of use, the single dose of chemical is dispensed diluted and distributed over the area to be treated. The consumer has thus paid only for the dose he has consumed and has no significant residue which he must store or safeguard, thus ensuring minimum cash flow and safety.
According to the present invention there is provided a fluid dispensing system comprising a dispenser attachable to a fluid reservoir to dispense metered quantities of fluid therefrom and a shuttle container which can be coupled to the dispenser to receive a metered quantity of fluid therefrom, the dispenser including a body defining a metering chamber having an inlet and an outlet, a valve assembly comprising an elongate slide carrying a first valve for opening and closing said outlet and a second valve for opening and closing said inlet, one said valve being resiliently retractable relative to the slide so that when the slide is longitudinally displaced from a first position to a second position, the first valve closes said inlet before the second valve opens said outlet and when the slide is longitudinally displaced from the second position to the first the second valve closes said outlet before the first valve opens said inlet, the shuttle container having a collar for engagement with the body of the dispenser and a spigot for engaging the elongate slide to displace said slide from the first position to the second position, one of the engaging ends of the spigot and slide having a drive recess and the other having a mating projection which when engaged in said recess locks the two against relative rotation locking means for inhibiting displacement of the slide from the first position to the second position when the slide is in a first angular orientation and allowing said displacement when the slide is in a second angular orientation, cooperating means on said dispenser body and said collar which can engage each other only when said mating projection engages said non-circular recess, said cooperating means when engaged constraining relative movement between said shuttle container and the dispenser so as first to allow the spigot to rotate said slide from the first angular orientation to the second angular orientation to release said locking means and thereafter displace the slide from the first position to the second position both in response to manipulation of the shuttle container relative to the dispenser, whereby to discharge the metered quantity of fluid from the dispenser into the shuttle container.